<!--
 * @Description: 
 * @Author: wanggang
 * @Date: 2019-11-18 09:58:15
 -->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .gra{
        width:300px;
        height:100px;
        background-image:linear-gradient(to bottom left,#000,#fff);
        border-top: 1px solid cornflowerblue;
        }
        .gra::before {
            content: '';
            width: 8px;
            height: 2px;
            background: aqua;
            position: absolute;
            top: 8px;
            left: 300px;
        }
        </style>
</head>
<body>
    <div class="gra"></div>
</body>
</html>